System for automatically testing a fluid specimen

ABSTRACT

A system for automatically testing a fluid specimen, e.g., urine, to indicate the presence of specified chemical components in the specimen. The system preferably utilizes an assaying device comprised of a collection cup and a cap which carries at least one test strip. The device includes an integrated aliquot delivery mechanism actuatable to wet the test strip with an aliquot delivered from the fluid specimen. The assaying device is configured to operate in conjunction with an electronic reader device capable of actuating the aliquot delivery mechanism and reading the reaction of the test strip. A preferred reader device defines a keyed receptacle for accommodating a complementary shaped cup housing in a particular orientation. The reader device is comprised of a camera for capturing the image of a test strip, an actuator for actuating an aliquot delivery mechanism, and a microprocessor/controller for (1) controlling the camera and actuator and (2) processing the image.

RELATED APPLICATIONS

This application is a division of U.S. Application Ser. No. 10/779,014,filed Feb. 13, 2004, which is division of U.S. Application Ser. No.10/072,154, filed Feb. 6, 2002, now U.S. Pat. No. 6,716,393, which is adivision of U.S. Application Ser. No. 09/444,926, now U.S. Pat. No.6,514,461, filed Nov. 24, 1999, which is division a Continuation-In-Partof U.S. application Ser. No. 09/245,175, now U.S. Pat. No. 6,342,183filed Feb. 5, 1999 by Murray Lappe, et al. U.S. applications Ser. No.08/832,957 filed Apr. 4, 1997 now U.S. Pat. No. 5,929,422; Ser. No.08/801,041 (now U.S. Pat. No. 5,916,815) filed Feb. 14, 1997; Ser. No.09/018,487 filed Feb. 4, 1998, now U.S. Pat. No. 6,036,092; and Ser. No.09/025,559 (now U.S. Pat. No. 5,902,982) filed Feb. 18, 1998 are alsorelated. The disclosures of the aforementioned applications are, byreference, incorporated herein.

BACKGROUND OF THE INVENTION

This invention relates generally to systems for automatically testingfluid specimens, e.g. urine or other body fluids, to detect chemicalsubstances or components therein. Such systems can be used, for example,to screen employee applicants for illegal drug use.

Employee drug testing typically involves an initial screening test toidentify specimens which are negative (i.e., no drugs present). Thistest is usually performed with a low cost immunoassay which is verysensitive to small quantities of drug metabolites. If a drug metaboliteis detected (referred to as “presumptive positive”), the specimen isthen subjected to a confirmation test which typically utilizes a highlyspecific test method, such as a gas chromatography/mass spectrometry(GC/MS), to identify the specific drug components in the specimen.

Traditionally, both the screening and confirmation tests were performedin a common facility, i.e., centralized laboratory. More recently,systems have been implemented which perform the screening test at alocal service site. They typically employ drug test kits which followthe tradition of home pregnancy test kits, i.e., they detect thepresence of a specific drug substance(s) in a urine specimen. Such drugtest kits generally identify, in human readable form, the drug(s) beingtested to indicate the presence (or absence) of that drug. The screeningtest result with respect to each particular drug, and to the specimen asa whole, can either be (1) negative or (2) presumptively positive. Ifpresumptively positive, then the specimen is generally sent to a remotelaboratory for confirmation testing.

Inasmuch as disclosure of a presumptive positive test result canadversely impact an applicant's record and could potentially lead tolitigation and employer liability, it is extremely important to preventthe inadvertent dissemination of test result data.

The aforementioned parent U.S. Pat. No. 6,342,183 describes an apparatusfor locally analyzing a specimen to qualitatively detect specifiedchemical components therein. The apparatus includes an assaying devicecomprised of a cup for collecting a fluid specimen and a cap carrying atleast one test strip for visually reacting to one or more specifiedchemical components in the specimen. The assaying device is preferablyconfigured to interact with a reader device capable of reading thereaction of the test strip to produce an electronic data output.

More particularly, the apparatus described in Application Ser. No.09/245,175 includes an open cup defining an interior volume foraccommodating a fluid specimen and an attachable cap configured formounting on the cup to seal the interior volume. The cap carries atleast one test strip and an integrated aliquot delivery mechanismactuatable to wet the test strip with an aliquot derived from the fluidspecimen. The aliquot delivery mechanism preferably comprises a pump inthe form of a plunger for forcing an aliquot of the fluid specimen ontothe test strip. The plunger can be actuated either manually orautomatically, e.g., by a piston controlled by a compatible readerdevice. The reader device preferably includes a microprocessor basedcontroller for actuating the aliquot delivery mechanism, a camera forproducing an image of the test strip, and a processor for analyzing theimage to produce test result data. The test result data, along withidentification data read from a label carried by the cap, can then bestored or communicated, e.g., via a modem.

SUMMARY OF THE INVENTION

The present invention is directed to an improved system and componentsthereof for automatically testing a fluid specimen, e.g. urine, saliva,or other body fluids, to indicate for the presence of specified chemicalcomponents in the specimen.

A system in accordance with the invention preferably utilizes anassaying device comprised of a collection cup and a cap which carries atleast one test strip. The device includes an integrated aliquot deliverymechanism actuatable to wet the test strip with an aliquot derived fromthe fluid specimen. The assaying device is configured to operate inconjunction with an electronic reader device capable of actuating thealiquot delivery mechanism and reading the reaction of the test strip.

A preferred reader device in accordance with the invention preferablydefines a keyed receptacle for accommodating a complementary shaped cuphousing in a particular orientation. The reader device is comprised of acamera for capturing the image of a test strip, an actuator foractuating an aliquot delivery mechanism, and a microprocessor/controllerfor (1) controlling the camera and actuator and (2) processing theimage.

In a preferred embodiment of the invention, the reader device preferablyalso includes a network connectivity device, e.g. modem, for enablingcommunication with a remote host computer. Although each reader devicecan operate independently as a stand-alone device, a preferred system inaccordance with the inventor employs a host computer or server, whichcommunicates, via a public and/or private network, with a plurality ofreader devices located at separate service sites. Each service site canbe configured to operate as a “thin client” with primary control beingexercised by the host computer via the network. Alternatively, primarycontrol can be exercised by the reader device at each site with onlyhigh level supervisory control coming from the host computer.

A preferred assaying device in accordance with the invention includes acap carrying multiple test strips including at least one component teststrip and at least one adulteration test strip. The cap is either formedof transparent material or is provided with transparent windows topermit external viewing of the test strips by the reader device camera.The cap preferably also carries one or more fiducial marks to facilitateimage processing. Further, the cap preferably also carries machinereadable identification information, e.g., a bar code label, topositively associate the specimen and test results with the correctindividual. Preferably, the cap does not bear any human readable indiciaidentifying the specimen donor or indicating test results.

A preferred test strip for testing for the presence of specific chemicalcomponents is configured with multiple latent lines (i.e., markings)which can become visible when the strip is wetted. The lines preferablyinclude a control or reference line and multiple drug lines each relatedto a different chemical component. If all of the latent lines visuallyappear within a certain test interval, e.g., up to eight minutes, afterthe strip has been wetted, this will indicate the absence of thespecific chemical components sought. However, if any of those specificchemical components are present in concentrations above a certainthreshold, their presence will suppress the appearance of one or more ofthe drug lines to indicate the presence of such chemical components.

A preferred reader device in accordance with the invention includes acamera located so that the cap is imaged onto the camera focal plane.The reader device includes a piston motor for driving a piston againstthe assaying device to deliver an aliquot to the test strips. The pistonmotor also moves a light shield into place around the cap enabling alight source to illuminate the cap to enhance the image for the camera.

A preferred automatic testing system in accordance with the inventionoperates as follows:

1. Fluid deposited into cup at local site; secure cap in tamper evidentfashion;

2. Site administrator places assaying device, i.e., cup and cap, into“keyed” receptacle of local reader and enters ID information;

3. Reader alerts host computer via communication network;

4. Initiate automatic reader operational sequence:

-   -   a. capture cap image and verify acceptability to proceed    -   b. run piston motor to advance piston into assaying device to        force fluid up channels to wet component and adulteration test        strips    -   c. capture cap image and verify acceptability to proceed    -   d. periodically capture additional cap images during development        interval up to about eight minutes    -   e. analyze captured image data to determine        -   1. test validity        -   2. test results    -   f. locally display test validity/results and/or communicate test        validity/results to Host computer    -   g. run piston motor to withdraw piston from cup

5. Site administrator removes cup from reader

The camera produces a digital representation of the image incident onthe camera focal plane. The processor then analyzes the digitalrepresentation to determine the color of the adulteration test strip andto locate visible markings on the component test strip coincident withthe reference and drug lines. Image analysis is preferably performed byinitially using fiducial marks on the cap to first precisely locate thecap image relative to a reference image. This can, for example, involverotating, translating, and/or scaling the cap image. Thereafter, thedigital representation of each test strip is examined to determine thepresence (or absence) of drug lines. This involves first locating thestrip reference line by effectively “drawing” a rectangular regionaround the reference line. The region can be considered as a rectangularmatrix of pixels having rows extending across the strip width, each rowbeing comprised of multiple column positions. For each row, the image isexamined to determine whether the pixel at each column position exceedsa threshold. The sum of pixels exceeding the threshold is determined foreach row. These row sums produce a graph whose x axis is related to theheight (i.e., number of rows) of the region and whose y axis is relatedto the values of the individual row sums. A bell shaped curve willresult whose peak locates the reference line. If no reference line islocated, the test is terminated. If the reference line is located, thenthe examination continues in order to locate the drug lines. Thedetection of drug lines is more difficult because the amplitude, i.e.,dark or light, of its pixels can vary widely dependent on severalfactors including wetting uniformity, urine color, variations amongsttest strips, exposure time, etc. In order to compensate for thesevariations, each drug region is preferably divided into left, center,and right portions. A drug line is presumed to occupy the center portionof each region. However, its exact position and exact width can varyattributable to the aforementioned factors. Moreover, its brightnessdifference in relation to neighboring areas can be very subtle. Hence, aprocedure is used to determine the weight of a line on a relative basis.

For example, for each drug region graph, the total area under each ofthree regions (left, center, right) is calculated. The left and rightregion areas are then numerically summed, and this resulting total areasum is multiplied by an experimentally determined “weighting value,”thus producing a weighted sum. If the area of the center region is lessthan or equal to the weighted sum, no line is present. By using urinesamples with known drug concentrations, a weighting value of 0.75 hasbeen experimentally determined to produce very acceptable results.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a block diagram of a system in accordance with the invention;

FIG. 2 is an isometric view of a preferred reader device in accordancewith the present invention;

FIG. 3 is an isometric view of a preferred cup and cap;

FIG. 4 is a plan view of the cap top surface;

FIG. 5 is a front sectional view taken substantially along plane 5--5 ofFIG. 2;

FIG. 6 is a top sectional view taken substantially along plane 6--6 ofFIG. 5;

FIG. 7 is a side sectional view taken substantially along plane 7--7 ofFIG. 5 showing the piston in its non-actuated position;

FIG. 8 is a side sectional view similar to FIG. 7 showing the piston inits actuated depressed position to force an aliquot to the cap forwetting the test strips;

FIG. 9A is a sectional view taken substantially along the plane 9A--9Aof FIG. 5 primarily showing the cup interior;

FIG. 9B is an enlarged sectional view showing the aliquot deliverymechanism of FIG. 9A in greater detail;

FIG. 10A is a diagrammatic view of a typical test strip used inembodiments of the present invention;

FIG. 10B is a diagrammatic view of the test strip similar to FIG. 10Abut modified to represent rectangular regions used to locate referenceand drug lines;

FIGS. 10C and 10D depict steps employed in analyzing a cap image tolocate a strip reference line; and

FIG. 10E depicts a step employed in analyzing a cap image to locate thepresence of a strip drug line.

DETAILED DESCRIPTION

Attention is initially directed to FIG. 1 which depicts a preferredsystem 20 in accordance with the invention comprised of multiple servicesites 22 respectively identified as 1 through N. Each service site canoperate independently as a stand-alone system to perform a screeningtest, as will be described hereinafter. However, in accordance with apreferred system configuration, the multiple service sites are connectedto a network 24, e.g., the Internet, for communication with a hostcomputer 26.

Each service site includes a reader device 28 configured to cooperatewith an assaying device 30 comprised of a specimen collection cup 32 anda cap 34. FIG. 1 depicts a functional block diagram of the reader 28whereas FIGS. 2 and 4-7 illustrate the reader's structuralconfiguration. The structural configuration of the assaying device 30 isillustrated in FIGS. 2-9.

Briefly, the reader 28 is comprised of a processor/controller 36programmed to operate (1) a camera 37 and light source 38 via a camerainterface circuit 40 and (2) a piston motor 42 via a motor controlcircuit 44. As will be discussed hereinafter, the piston motor 42operates to deliver an aliquot from a specimen in the cup 32 to one ormore test strips in the cap 34. The test strips each produce a visiblereaction in response to being wetted by the aliquot. The camera 37 andlight source 38 operate together to capture an image of the teststrip(s) enabling the processor/controller 36 to process the image todetermine test validity and whether the specimen is free of chemicalcomponents being monitored. The reader 28 preferably operates inconjunction with an input/output device 46 which enables a siteattendant to enter information, e.g., donor identification information,via a device such as a touch pad or keyboard, and to view information,e.g. via an LCD display, provided by the processor/controller 36.

The processor/controller 36 is also preferably connected to the network24 via a suitable connectivity device 48, e.g., a modem. This enablesthe reader to upload data, e.g., test results, billing information, etc.to the host computer 26. It also allows the host computer to exercisesupervisory control over the processor/controller 36.

Attention is now directed to FIG. 2 which illustrates the exteriorconfiguration of the reader housing 60. The housing is essentiallycomprised of a base portion 62, a head portion 64, and an enclosureportion 66, bridging the base and head portions. A receptacle 68 isdefined between the base and head portions for receiving an assayingdevice 30 above a keyed recess 70 formed on base platform 72. The keyedrecess 70 is shaped complementary to the lower periphery of the assayingdevice 30 to place the device in a specific orientation relative to headportion 64. The assaying device 30 is comprised of an open collectioncup 32 and a detachable cap 34. The cup 32 defines an interior volumefor collecting a fluid specimen, e.g. urine. After the fluid specimenhas been deposited into the cup 32, the cap 34 is mounted thereon toseal the interior volume and prevent the fluid specimen from leaking.Inasmuch as each assaying device 30 is intended to be used only once tocollect a single specimen, it is preferably fabricated via relativelylow cost plastic molding processes.

It can be noted in FIG. 3 that the cup 32 has an irregular lowerperiphery 76 particularly configured to mate with the keyed recess 70.The periphery 76 includes an enlarged front portion 78 and a reducedrear portion 80. The reduced rear portion 80 is bounded by flat fingergrip sides 82 having raised surface features 84 extending to an obliquewall surface 86. This irregular configuration of the cup facilitateseasy manual handling of the cup enabling it to be readily grasped by thehand of a user and/or administrator. The cup enlarged portion 78preferably includes an area 88 characterized by multiple vertical fins90. This area 88 functions as a key or registration area to which anindex area 92 on the cap 34 is aligned to assure proper cap/cup sealing.Markings are preferably provided on the cup exterior to indicate maximumand minimum fill levels.

Briefly, the cap 34 is comprised of a substantially circular member 94having a top exterior surface 96 and a depending flange or skirt 98. Theskirt 98 has a primarily knurled outer surface 100 that preferablydefines flat areas 102 and the aforementioned index area 92. The indexarea 92, which may be defined by vertical slots, is preferably used toalign with the aforementioned cup area 88 to visually indicate to a userthat the cap has been properly installed onto the cup. The cap 34 ispreferably installed onto the cup via a mating thread 104. The cap 34preferably carries a stop tooth 107 which rotates into engagement withthe end fin 90 when the cap is properly installed onto the cup. Whenproperly installed, the cap index area 92 will be aligned with the cupregistration area 88. Alternative mounting mechanisms, e.g., bayonetmount, can be used to couple the cap 34 to the cup 32.

Provision is preferably made to include a tamper evident seal toimmediately indicate to a user whether an assaying device, once sealed,has been tampered with. More particularly, note in FIG. 3 that the captop surface 96 carries a label 106 having a first portion 108permanently adhered to the surface 96. A second label portion 110extends beyond the edge of cap 34 and is intended for sealing againstcup area 111 immediately beneath the cup finned area 88. The labelportion 110 carries a suitable adhesive on its undersurface which, priorto use, is protected by release paper 112. When the release paper isstripped away, label portion 110 can be sealed against cup area 111 toassure that cap 34 cannot be removed from cup 32 without that fact beingimmediately evident. The label 106 preferably also includes a perforatedtear-off third portion 113 which can be affixed to a “B” container incase of split specimen collections, or in the event that a manual chainof custody record is required.

The cap top surface 96 (FIG. 4) is either transparent or at leastdefines one or more transparent areas 114, e.g., windows 114A, 114B, and114C for enabling a test strip mounted beneath each window to be visibletherethrough. As will be discussed hereinafter, the cap defines one ormore compartments each of which accommodates a test strip 115 which,when wetted by a fluid specimen, reacts to provide a visual indicationindicative of a characteristic of the specimen.

In the exemplary embodiment illustrated, the window 114C covers a teststrip intended to detect specimen (1) authenticity and (2) adulteration.As is well known, a freshly voided urine specimen can be authenticatedby a test strip which senses various characteristics includingtemperature and/or creatinine content of the specimen. Adulteration ofthe specimen can be detected by a test strip sensitive to exogenouscomponents, e.g. pH and/or nitrites. Preferably, the test strip changescolor when wetted and detection is achieved using a colormetrictechnique Larger windows 114A and 114B are intended to reveal teststrips 115 for detecting various specific chemical components typicallyassociated with illegal substance abuse. FIG. 10A schematicallyrepresents such a component test strip 116 showing multiple latent lines117 visually represented on an indicator portion 118 extending from anabsorbent portion 119. The latent lines 117 typically include one ormore reference or control lines 117R and multiple drug lines 117D₁,,117D₂, etc., each for a different drug or chemical component to bedetected. If all of the lines visually appear within a certain testinterval, e.g., up to eight minutes, after the absorbent portion 119 hasbeen wetted, this will indicate the absence of the specific chemicalcomponents sought (i.e., a “negative” test). However, if any one ofthose specific chemical components is present in concentration above acertain threshold, its presence will suppress the appearance of one ormore of the lines to indicate to an astute observer and/or computerbased reader, the presence of that component.

The cap top surface 96 (FIG. 4) preferably additionally defines aprimary bar code area 120, a secondary bar code area 121, and one ormore fiducial marks 122, to be discussed hereinafter. All of the windows114, bar code areas, and fiducial marks are arranged around a plungerhole 124 within a tightly dimensioned image field 125 suitable for beingimaged onto the focal plane of camera 37. In an exemplary embodiment,the image field has width and height dimensions respectively equal to1446 mils and 1084 mils which is imaged onto a camera view field having640 pixels horizontally and 480 pixels vertically.

The internal structure and operation of a suitable assaying device 30 isdescribed in aforementioned parent U.S. Pat. No. 6,342,183, whosedisclosure is, by reference, incorporated herein. Briefly, as depictedin FIGS. 5-9, the assaying device cap 34 defines descending concentricouter and inner tubular walls 126 and 127. Multiple passageways 128A,128B, 128C, 128D extend vertically between the outer and inner tubularwalls 126 and 127. Each passageway 128 defines a passageway inlet 129 atthe lower end of inner tubular wall 127 and a passageway outlet 130proximate to compartments 131, respectively accommodating component oradulteration test strips 132, located beneath the aforementioned windows114. Overflow Basins 136, 138 are respectively located adjacent to thecompartments beneath windows 114A, 114B to collect any fluid overflow.

The inner floor 150 of the cup 32 is configured to define an open well152. When the cap 34 is installed on the cup 32, the lower end of theouter tubular wall 126 extends into the well 152 and essentially forms aclosed chamber 154 for isolating a portion of the fluid specimen. Aplunger 160, comprised of a plunger pin 162 and plunger element 164, ismounted in inner tubular wall 127 above chamber 154. The plunger element164, is formed of soft conforming material able to seal against theinner surface of inner tubular wall 127. The opening 124 in the cap topsurface 96 provides access to enable the pin 162 to be depressed.

As the plunger element 164 is depressed into chamber 154, the fluidtherein is displaced upwardly via inlet 129 through multiple passageways128. These passageways, 128A, 128B, 128C, 128D respectively extend tothe aforementioned test strip compartments located below theaforementioned cap windows 114. Thus, depression of the plunger 160within the inner tubular wall 127 displaces fluid from the chamber 154to deliver an aliquot to each of the compartments 131, each compartmentaccommodating a separate strip 115 of test material. The device 30 isconstructed and dimensioned so that each aliquot comprises a specificvolume of fluid.

Attention is now directed to FIGS. 5-8 which illustrate the internalstructure of the reader housing 60. The housing 60 is formed by a baseplate 150 having a vertical frame member 152 secured thereto. The baseplate 151 is weighted by block 154 for stability. A shell 160 is affixedto the base plate 150 and frame member 152. The shell includes a baseplatform member 72 which defines the aforementioned keyed recess 70. Theshell 160 additionally includes a rear shell member 162 which encloses arear compartment 164 housing the reader electronic circuit board(s) 166.An upper shell member 170 encloses a top compartment 172 which housesthe camera 37, light source 38 and piston motor 42. These devices arestructurally supported on arm 176 projecting forwardly from frame member152.

A piston subassembly 180 is mounted for vertical reciprocal motiontoward and away from base plate 150. The piston subassembly is comprisedof a support arm 182 projecting forwardly from slide block 184 mountedfor linear movement along guide rails 186. The support arm 182 carries apiston member 186 aligned with opening 124 in the cap of an assayingdevice 30 placed in the keyed recess 70. A lead screw 188 is threadedinto hole 190 in support arm 182. The lead screw can be selectivelyrotated either clockwise or counterclockwise by piston motor 42 to movethe slide block 184 either up or down. FIG. 7 depicts the piston member186 in its up position providing sufficient clearance to allow anassaying device 30 to be placed on or removed from the keyed recess 70.FIG. 8 shows the piston member 186 in its down position extending intocap opening 124 to depress plunger 160 to displace fluid from thespecimen in cup 32 to wet the test strips 115.

It should also be noted that the piston subassembly 180 includes asubstantially cylindrical light shield 192 mounted on slide block 184.The light shield 192 defines a lower edge 194 which seals against thecap top surface 96 when the slide block is in its down position shown inFIG. 8.

The camera 37 can comprise a commercially available digital camera andappropriate optics for imaging the field 125 (FIG. 4) onto the camera'sfocal plane. The camera preferably has a resolution of 640(horizontal).times.480 (vertical) pixels. Imaging is enhanced byselective illumination of light sources 38 and by the shielding effectafforded by light shield 192.

A preferred operational sequence for automatically testing a fluidspecimen is represented by the following sequential steps:

1. Donor at a local site deposits fluid into cup 32; site administratorenters identification information and secures cap 34 in tamper evidentfashion;

2. Administrator places cup/cap into “keyed” receptacle 70 of localreader 28 and enters ID information;

3. Reader 28 alerts host computer 26 via communication network 24;

4. Host computer 26 (or administrator) initiates reader operationalsequence:

-   -   a. camera 37 captures cap image and processor 36 verifies        acceptability to proceed    -   b. processor 36 runs piston motor 42 to advance piston 164 into        cup to force fluid up channels 128 to wet component and        adulteration test strips    -   c. camera captures additional cap image and verify acceptability        to proceed    -   d. periodically capture additional cap images during development        interval up to about eight minutes    -   e. processor analyzes captured image data to determine        -   1. test validity        -   2. test results    -   f. processor 36 displays test validity/results on local I/O 46        and/or communicates test validity/results to Host computer 26    -   g. processor 36 runs piston motor to withdraw piston from cup

5. Site administrator removes cup from reader

In step 1, the site administrator first enters donor and client (e.g.,employer) information via I/O devices 46 into a database stored eitherin processor 36 or host computer 26. The donor voids into a cup 32 andthe cap 34 is sealed thereon. The label is extended from the cap to thecup to assure that it is sealed in tamper evident fashion. Preferablythe administrator and donor then initial the sealed label and review thechain of custody document. The donor and administrator both apply theirsignatures to the signature pad and a copy of the chain of custodydocument is printed and given to the donor. The donor is then dismissed.Preferably the cup/cap is then placed in the reader.

Step 4 of the foregoing sequence is automatically executed under thecontrol of programmed microprocessor 36. In step 4 a, the piston has notyet been inserted into the cup and may partially obscure the field ofview. In addition, since the piston is not down, the light shield isonly partially effective, and extraneous light may enter, furtherobscuring details. Nevertheless, an initial image is captured by thecamera to examine the primary barcode 120 and other cap features todetermine if it is valid. If the barcode is not valid, this fact isdisplayed to the site administrator for further action. An invalidbarcode can indicate that the cup is inserted incorrectly, that there isno cup there at all, or that a “fake” cup has been inserted. If theadministrator cannot resolve the issue and the barcode is indeedinvalid, testing is aborted and the sealed cup is sent for laboratoryanalysis.

In step 4 b, processor 36 runs the piston motor 42 to lower the piston164 a predetermined distance. This also lowers the light shield 192 intoplace against the cap top surface 96 so that the light source 38 is thenthe only source of light illuminating the cap top. The light source 38preferably comprises multiple green LED's inasmuch as the lines thatappear on typical component test strips exhibit the highest contrastwhen viewed in green light. With the piston in its down position, it nolonger obscures any cap features within the image field 125.

In step 4 c, another image of the cap is captured and processed todouble-check the primary barcode results from the previous step and toread the secondary barcode 121 and the fiducial marks 122. The fiducialmarks 122 are small features printed on the cap directly above the teststrip windows 114A, 114B and serve as reference points for subsequentprocessing steps to assure accurate image analysis. Preferably, thebarcode labels have their own fiducial marks, which allow the barcodesto be found and read even if the label is askew. If all barcodes andfiducial marks can be located and properly read, then operation proceedsto step 4 d. Otherwise, the site administrator is alerted and he/shedecides whether to proceed or not.

The test strips take between two and eight minutes to develop. Duringstep 4 d, images are periodically captured and during step 4 e, theimages are processed and analyzed. Steps 4 d and 4 e are executed in aniterative loop. If all latent lines become visible after two minutes,the test is concluded and operation proceeds to step 4 f. Otherwisesteps 4 d and 4 e are executed every minute until eight minutes haveelapsed. If any of the drug or control lines do not become visible, theassaying device is sent to the lab for further analysis.

The image analysis executed in step 4 e includes an extensive procedureto be discussed hereinafter for discerning a color change on theadulteration test strip and visible reference and drug lines on thecomponent test strip. The detection of these lines can be reasonablychallenging because the amplitude, i.e., dark or light, of its pixelscan vary widely dependent on several factors including variations intest strips, in wetting, in urine color, etc. In order to produce anoptimum image for analysis, a sequence (e.g., 8) of images is actuallycaptured. These multiple images are then mathematically summed dividedby the number of images in order to produce an integrated image in whichthe random electrical and optical “noise” has been reduced by this“averaging” process. This integrated image is then used in thesubsequent line detection procedure:

-   -   4e(1) The fiducial marks 122, which had been found to exist in        step 4 c, are now located precisely by looking in a restricted        region (as a consequence of the cup being physically positioned        by keyed recess 70) and finding the centroid of the individual        fiducial marks. This determines their exact locations within the        camera field of view (i.e., 640×480).    -   4e(2) Based on the locations of the fiducial marks, the image is        now rotated, translated, minified, and or magnified as necessary        so that the resulting image has the fiducial marks 122 (and        hence all other cap features) in “standard” positions which is        hence presumed for all subsequent operations.    -   4e(3) Using a “map” of the features present on the cap top, each        test is individually examined. Although the two test strips can        in fact differ in the number of lines present and their specific        locations, for the sake of simplicity, the operations on only        one typical test strip will be described.    -   4e(4) Based on known default reference and drug line positions,        non-overlapping rectangular regions 200 are “drawn” around each        reference line 117R and drug line, e.g., 117D (FIG. 10B).    -   4e(5) For the region 200 which contains the reference line 117R,        row sums are produced. The number of pixels summed for each row        is the “width” of the test strip (e.g., 32 in FIG. 10C), the        number of total row sums for each region is the “height” of the        individual region (e.g., 48 in FIG. 10C). Each of these row sums        produces a graph (FIG. 10D) whose X axis is related to the        “height” of the region, and whose Y axis is related to the        values of individual row sums. Let it be assumed that individual        row sums will be smaller for darker horizontal rows and larger        for lighter horizontal rows. The resulting graphs are then        preferably normalized so that the Y axis values are between 0        and 100, and then subtracted from 100 so that the darkest row in        a given region has the value 100 and the brightest row in a        given region has the value 0. Bell shaped curves will result        (presuming a drug or control line is present) as depicted in        FIG. 10D.    -   4e(6) The reference line 117R must be located in order to        proceed further and its exact position must be determined in        order to locate the best estimated positions of the drug lines        for further processing. The graph for the reference line is        examined for a maximum value, which represents the reference        line center position. After the center position is located, the        regions drawn in substep 4e(4) above are redrawn to center the        reference line and drug lines in their respective regions.    -   4e(7) For each drug region, row sums and the resulting graph are        produced as described in substep 4e(5) above.    -   4e(8) Each drug region graph is divided into three equal parts,        a left, center, and right part as represented in FIG. 10F. The        drug line is presumed to occupy the center portion. However, its        exact position and width can vary, and its brightness difference        in relation to the neighboring area may be very subtle. Based on        different wetting conditions, a dark condition in one region can        in fact be lighter than a not-dark condition in another region.        Hence, a relative mechanism is used to determine the presence or        absence of a drug line.    -   4e(9) For each drug region graph, the total area under each of        the three regions (left, center, right) is calculated. The left        and right region areas are then numerically summed, and this        resulting total area sum is multiplied by an experimentally        determined “weighting value”, thus producing a weighted sum. If        the area of the center region is greater than this weighted sum,        a decision is made that a line is present. If the area of the        center region is less than or equal to the weighted sum, a        decision is made that no line is present. By using urine samples        with known drug concentrations, a weighting value of 0.75 has        been found to produce very acceptable results. In order to        conceptually understand what is going on, presume that the graph        is perfectly symmetric and the drug line is centered in the        graph, hence the graph will appear as a bell curve (FIG. 10F)        (this is typical of the actual graphs produced) if a line is        present, or at the other extreme, will appear as a flat line if        no drug line is present. In the case of a flat line, then the        summed areas of the left and right region will be exactly twice        (2*X) the area of the center region (X). If the 2*X value is        weighted by 0.75, the resulting area is now 1.5*X, which is        greater than X. Hence no drug line is considered present. In        fact, the weighting value would have to be less than 0.5 for a        line to be considered present. As the center region grows in        amplitude, its area reaches a point that it is now greater than        the weighted sum of the left and right regions, and a line is        considered present. Note that the presence or absence of a line        is not determined by the exact position or shape of this curve,        nor by the exact amplitudes of the dark and light components,        which can vary widely based on various factors including the        degree of wetting, the color of the urine, the particular lot of        test strips, the time of exposure, extraneous material on the        test strip, and shadows and/or reflections.

All of these variations are compensated for in the relatively simple andconcise mathematical procedure described which allows the presence orabsence of drug lines to be repeatedly determined to a controllable,high degree of accuracy.

Once all adulteration test strips have been examined for color and allcomponent test strips examined for visible lines, a final test result,for adulteration and identification of drug lines present and/or absent,is locally displayed and/or communicated to the host computer inaccordance with aforementioned step 4 f.

The foregoing describes applicants' preferred system for automaticallytesting fluid specimens to detect specific chemical components therein.The preferred system includes an assaying device comprised of a fluidcollection cup and a cap carrying one or more test strips configured toproduce visually discemable indications of the components of thespecimen and/or specimen adulteration. The visual indications are readby an imager, e.g., digital camera, and interpreted by a processor whichexecutes an analysis procedure to interpret the visual indications. Theresulting test results are reported locally or via a communicationsnetwork to a host computer. Thus, systems in accordance with theinvention can quickly (e.g., in less than 15 minutes) and locallyautomatically test a fluid specimen to provide accurate qualitative testresults. The system both assures the confidentiality of donor/specimentest results (by using machine readable, rather than human readable,markings) and a closely controlled chain of custody procedure.

Although a preferred embodiment has been described, it is understoodthat many modifications and variations will occur to those skilled inthe art which fall within the intended scope of the invention as definedby the appended claims.

1. An apparatus comprising: an assaying device reader comprising ahousing and a camera, said housing including a base portion and a headportion; and an assaying device comprising a cup and a test strip, saidcup be operable to hold a fluid specimen, said test strip being operableto provide a visual indication of at least one property of the fluidspecimen, said base portion directly contacting said assaying device andmaintaining said assaying device in a substantially fixed positionrelative to said camera, said camera being coupled to said head portionand operable to acquire an image of said test strip.
 2. The apparatus ofclaim 1, one of said base portion and said cap defining a recess, theother of said base portion and said cup presenting a projection, saidrecess receiving said projection in a substantially complemental fashionto thereby inhibit relative lateral movement between the cup and thebase portions.
 3. The apparatus of claim 2, said recess and saidprojection cooperating to maintain said cup in a predeterminedorientation relative to the camera.
 4. The apparatus of claim 2, saidrecess and said projection having a substantially similar, non-circularshape.
 5. The apparatus of claim 1, said device reader further includinga piston shiftably coupled to said head portion and configured to shiftinto and out of engagement with said assaying device.
 6. The apparatusof claim 1, said device reader further including at least one lightsource for illuminating said test strip.
 7. The combination of claim 1,said device reader further including a light shield movably mounted insaid head portion for movement toward said assaying device to minimizestray light on said test strip.